City of Glass (Clare novel)

City of Glass is the third novel in The Mortal Instruments series by Cassandra Clare, published in 2009. It is a young adult fantasy novel that continues the story of Clary Fray as she navigates the world of Shadowhunters, demons, and Downworlders.

The novel's title refers to Alicante, the capital city of Idris, the Shadowhunter homeland. Much of the story takes place within Alicante's protective walls, including significant locations such as the Gard, the central Shadowhunter council, and Lake Lyn, a body of water with powerful, dangerous properties.

City of Glass deals with themes of family secrets, forbidden love, prejudice, and sacrifice. Clary, against the wishes of the Clave, travels to Alicante to find a way to save her mother, Jocelyn. Once there, she becomes entangled in a complex web of political intrigue and must learn to harness her unique powers to protect the Shadow World from Valentine Morgenstern and his demon army.

The novel is significant within the series for resolving several major plot points, including revelations about Clary's heritage and the establishment of a fragile peace between the Shadowhunters and the Downworlders. It also introduces new characters and explores the history and culture of the Shadowhunter world in greater depth.